Monte Carlo simulation of a prototypical patient dosimetry system for fluoroscopic procedures

Lukas Goertz, Panagiotis Tsiamas, Andrew Karellas, Erno Sajo, Piotr Zygmanski

Research output: Contribution to journalArticle

4 Scopus citations

Abstract

The purpose of this study is to investigate feasibility of a novel real-time dosimetry method for fluoroscopically guided interventions utilizing thin-film detector arrays in several potential locations with respect to the patient and x-ray equipment. We employed Monte Carlo (MC) simulation to establish the fluoroscopic beam model to determine dosimetric quantities directly from measured doses in thin-film detector arrays at three positions: A-attached to the x-ray source, B-on the couch under the patient and C-attached to the fluoroscopic imager. Next, we developed a calibration method to determine skin dose at the entry of the beam (Dentr) as well as the dose distribution along each ray of the beam in a water-equivalent patient model. We utilized the concept of water-equivalent thickness to determine the dose inside the patient based on doses measured outside of the patient by the thin-film detector array layers: (a) A, (b) B, or (c) B and C. In the process of calibration we determined a correction factor that characterizes the material-specific response of the detector, backscatter factor and attenuation factor for slab water phantoms of various thicknesses. Application of this method to an anthropomorphic phantom showed accuracy of about 1% for Dentr and up to about 10% for integral dose along the beam path when compared to a direct simulation of dose by MC.

Original languageEnglish (US)
Pages (from-to)5891-5909
Number of pages19
JournalPhysics in medicine and biology
Volume60
Issue number15
DOIs
Publication statusPublished - Aug 7 2015
Externally publishedYes

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Keywords

  • entrance dose
  • fluoroscopy
  • integral dose
  • Monte Carlo
  • peak skin dose
  • real-time dosimetry
  • thin-film detector arrays

ASJC Scopus subject areas

  • Radiological and Ultrasound Technology
  • Radiology Nuclear Medicine and imaging

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